Palbociclib combined with endocrine therapy in heavily pretreated HR+/HER2- advanced breast cancer patients: Results from the compassionate use program in Spain (PALBOCOMP)
Luis Manso,
Cristina Hernando,
María Galán,
Mafalda Oliveira,
Miguel A. Cabrera,
Raquel Bratos,
César A. Rodríguez,
Manuel Ruiz-Borrego,
Salvador Blanch,
Antonio Llombart-Cussac,
Juan I. Delgado-Mingorance,
Iñaki Álvarez-Busto,
Isabel Gallegos,
Lucía González-Cortijo,
Serafín Morales,
Elena Aguirre,
Blanca A. Hernando,
Ana Ballesteros,
José E. Alés-Martínez,
Cristina Reboredo,
Amparo Oltra,
María González-Cao,
Marta Santisteban,
Diego Malón,
Isabel Echeverría,
Elisa García-Garre,
Estela Vega,
Sònia Servitja,
Raquel Andrés,
Carlos E. Robles,
Rafael López,
Elena Galve,
María J. Echarri,
Marta Legeren,
Fernando Moreno
Affiliations
Luis Manso
Hospital Universitario 12 de Octubre, Madrid, Spain
Cristina Hernando
Hospital Clínico Universitario de Valencia, Valencia, Spain
Background: This study evaluated efficacy and safety of palbociclib, a CDK4/6 inhibitor, in heavily-pretreated hormone receptor-positive and human epidermal growth factor receptor 2-negative (HR+/HER2-) metastatic breast cancer (mBC) patients during the compassionate use program in Spain from February 2015 to November 2017. Patients and methods: Patient data were collected retrospectively from 35 hospitals in Spain. Patients with HR+/HER2- mBC who had progressed on ≥4 treatments for advanced disease were eligible. Results: A total of 219 patients received palbociclib in combination with aromatase inhibitors (110; 50.2%), fulvestrant (87; 39.7%), tamoxifen (8; 3.6%) or as single agent (10; 4.6%). Mean age of the patients was 58 years; 31 patients (16.1%) were premenopausal and 162 (83.9%) were postmenopausal at the beginning of treatment with palbociclib. Patients had received a median of 3 previous lines of endocrine therapy (ET) for advanced disease. Real-world tumor response (rwTR) and clinical benefit rate were 5.9% (n = 13) and 46.2% (n = 101), respectively. The median real world progression-free survival (rwPFS) was 6.0 months (95% CI 5.7–7.0) and the median overall survival was 19.0 months (95% CI 16.4–21.7). Subgroup analysis revealed a significant difference in median rwPFS in patients treated with palbociclib plus fulvestrant depending on the duration of prior treatment with fulvestrant monotherapy (>6 versus ≤6 months; HR 1.93, 95% CI 1.37–2.73, p < 0.001). The most frequently reported toxicities were neutropenia, asthenia, thrombopenia and anemia. Conclusions: Palbociclib can be an effective and safe treatment option in patients with heavily pretreated endocrine-sensitive mBC, especially in those with longer PFS to previous ET.